Is it possible to make multi-parameter properties?

Question

Is there a way to do something like this:

class blabla
{
   string[] a;
   string ciao(int row, string text)
   {
       set { a[row] = text;}
       get { return a[row;}
   }
}

(yeah i know i can just make my own method eventually)

Answer 1

This best you can do is using the index property, this:

class Foo
{
 string[] row;

 string this[int row]
 {
    set {a[row] = value;}
    get {return a[row];}
 }
}

Then, you access it using the [] operator:

Foo f;
f[1] = "hello";

It's not possible to have a named property that behaves this way.

As an interesting aside, there's no reason, from a .NET, that properties can't be parameterized. If you look at the PropertyInfo class you can see that a property is just a get method and a set method, both of which can take parameters. In fact this is how the index property works (along with an attribute). It's just that C# doesn't expose this functionality through the language.

Answer 2

You can make an indexer property

public string this[int index]

Overloads the [] operator on your class, allowing you to take a parameter between the [] and after the =

You could change the type of the index parameter, but this will probably be confusing to the caller.

http://msdn.microsoft.com/en-us/library/aa288464(v=vs.71).aspx

class blabla
{
   private string[] a;
   string this[int row]
   {
       set { a[row] = value;}
       get { return a[row;}
   }
}

The syntax works so that the type of value is specified by the return type of the overloaded operator.